Electrical connectors



R. F. KROLAK June 20, i967 ELECTRI CAL CONNECTORS 2 Sheets-Sheet 1 FiledJune l5, 1964 mwa, Nh.

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0 fma! `fune 20, 1967 R. F. KROLAK ELECTRICAL CONNECTORS Filed June l5,1964 United States Patent Oil tice 3,327,282 Patented June 20, 19673,327,282 ELECTRICAL CONNECTORS Ronald F. Krolak, North Riverside, Ill.,assignor to Amphenol Corporation, a corporation of Delaware Filed .Iune15, 1964, Ser. No. 374,907 6 Claims. (Cl. 339-63) This invention relatesto electrical connectors. It is the general aim of the invention toprovide an improved electrical connector suitable for atomic missileusage and having all lof the advantages of earlier types relating toresistance to adverse environmental conditions, ruggedness ofconstruction, compactuess, and ease of servicing, yet having greatlyincreased reliability.

It is a specific object of the invention to provide a connector of thegeneral type wherein the individual contacts may be aixed to theirconductors prior to assembly in the plug or receptacle of the connectorand may thereafter be quickly, easily and conveniently mounted inoperating position in the plug or receptacle of the connector and aseasily removed therefrom for inspection or replacement, yet with amechanical arrangement of parts such that any malfunctioning due tomisalignment of the contacts is almost entirely eliminated, and by adesign wherein so-called false checkouts are eliminated.

It may be explained that in some prior types of connectors, particularlywhen subjected to misuse or abuse, it is possible for the plug andreceptacle of the connector to be improperly coupled to each other, yetin a condition that may function intermittently in a manner not alwaysdetected by circuit tests but with latent defects that can becatastrophic in actual operation.

Obviously, the accomplishment of the foregoing objects requires thedevelopment of a connec-tor having a large number of features that areindividually recognized as being desirable, =but it further requires thereconciliation of electrical, mechanical and environmental factors thathave heretofore been believed to be impossible of simultaneousaccomplishment, or at least so antagonistic to each other as to precludesuccessful combination.

As a'solution to this generally recognized dilemma, the presentinvention proposes utilization of a plug and receptacle wherein bothsets of contacts are individually removable by application of properlydesigned removal tools inserted from the front face of the connector,yet withthe plug body being of the so-called hard front, closed entrytype wherein the plug contacts are housed in hard, rigid dielectricmaterial with openings sized to exclude oversize or misaligned pins, sothat the likelihood of misalignment of the connector contacts duringengagement of the plug and receptacle is minimized. The presentinvention further proposes a relationship of parts such that, should anysignicant misalignment occur, it will infallibly prevent completion ofthe current path through the connector parts in a manner to be instantlyand unquesionably apparent in the pre-flight testing of the missilecircuitry.

The present preferred embodiment of `the invention speiccally designedfor the control circuitry of an atomic missile is illustrated in thedrawings of this application, wherein:

FIGURE l is a greatly enlarged quarter-sectional view through a multiplecontact connector of the pin-andsleeve type;

FIGURE 2 is a fragmental front elevational View of the front face of theplug Ibody of the connector shown in FIGURE 1;

FIGURE 3 is a detail perspective of a latch release member utilized inthe illustrated connector;

FIGURE 4 is a perspective view of Contact removal tool adapted to beutilized with the sleeve contacts used in the plug of the connector;

FIGURE 5 is a greatly enlarged central sectional view of a contactretention clip as used in both the plug and receptacle, showing itsoperating relationship with a latch Irelease tube of the plug;

FIGURE 6 is a similarly enlarged detail sectional view of a contactretention clip, taken substantially on the plane of the line 6 6 ofFIGURE 5;

FIGURE 7 is a fragmental sectional view taken through a contact cavityof the plug and showing the mode of operation of the contact latchreleasing means therefor; and

FIGURE 8 is a fragmental sectional view similar to FIGURE 7 but showingthe manner -of removal of the sleeve contact from the plug body.

With reference now to FIGURE l particularly, the connector receptacle 10and plug 11 each have an exterior tubular metal shell 12, 13, having theforward ends arranged to telescope within each other and to provide aperipheral seal for the interior of the connector by an O ring 14,carried in the internal groove 15 of the receptacle shell 12. Theforward end of the receptacle shell 12 is threaded at 16 to receive athreaded coupling-collar 17 having an internal spring ring 18 seated inan internal groove 19 adapted to bear against the ange 20 of the plugshell 13 to removably draw the plug and shell into coupled relation. Asshown, the receptacle shell is provided with one or more internalkeyways 21 and the forward end of the plug shell has a corresponding keyor keys 22 to maintain the desired angular relationship betwen the plugand its receptacle and to thus properly polarize the various individualcontacts therein. As illustrated, the receptacle and plug each have acable support nut 23, 24 threaded to the rearmost end of the shells 12and 13, with rearwardly extending arms 25 and 26 to support cable clamps(not shown) in the conventional manner.

The plug and receptacle each have a multi-part dielectric insert inwhich the individual contacts are supported. In the receptacle 10, thisinsert includes a thin, flat, rigid disc 27, generally referred to as ananti-delection disc, transversely disposed in the shell 12 and carryingone or more contact retention clips 28 to support the individual pincontacts of the receptacle. The disc 27 is also preferably provided witha resilient sealing member 29 Ibondedto its forward face and, as shown,has a resilient grommet 30 similarly bonded on its rearward face. Theparts 27, 29 and 30 are all locked in the shell 12 by a spring ring 31each of these parts have aligned apertures in registry with each of thecontact retention clips 28, to provide an elongated longitudinal contactcavity 32 running entirely through the insert at the location of eachcontact. The lrearward ends of each of these cavities, in the area ofthe resilient grommet 30, have a plurality of sealing risers 33 formedintegrally with the grommet.

In the connector illustrated, the receptacle portion 10 carries the malecontacts which, as shown, include a cylindrical sleeve 34 adapted toreceive the insulating layer 3. 35 of a flexible conductor 36 whichextends into a sleeve portion 37 of the contact wherein its is held byany conventional means, such as crimping. The contact illustrated has apositioning shoulder 38 from which a shank por- 'tion 39 extendsforwardly to a taper 41 terminating in fa reversely facing shoulder 42on the head portion 43 of 'the contact, which carries the forwardlyprojecting cylindrical contact pin 44.

The connector plug 11 also includes a multi-part di- Aelectric insertincluding an anti-deflection disc 51 held within the connector shell -bya locking ring 52, with a resilient sealing grommet S3 Ibonded to therea-r face of the disc and a sealing member -54 similarly bonded on itsfront face, but in the plug there is also provided a so-called hardfront body member 55 formed of hard, rigid, smooth-surfaced insulatingmaterial. As shown, the body 55 is of 'generally cylindrical shape, andextends from a generally flat front face 56 to a rearward face 57whichfmay bear against or be bon-ded tothe sealing member 54. Asillustrated, the body member -55 has a rearwardly and outwardlyextending flange S engaging a rearwardly facing shoulder 59 on theinside of the plug shell 13 so that the parts 51, 54 and 58 may be heldclamped in pressure relationship by the locking ring 52.

The anti-deflection disc y51 of the plug is also provided with one ormore contact retention clips 61. These clips may 4be identical to theclips 28 of the receptacle and are best illustrated in FIGURES 5 and 6,wherein it will 'be seen that each individual clip 61 consistsessentially of a short tubular sleeve 62 having a segmental .mountingflange 63 adapted to be molded into the anti-deflection disc 51 or 27 orsecured between plural laminations thereof as shown in FIGURE 5. Thesleeve 62 is longitudinally split, preferably by four or tive slots 64which extend from a point near the mounting flange to the forward end ofthe sleeve. These lslots divide the sleeve into several independentlyflexible segments 65, each of which is provided with an inwardlyinclined .latch tooth 66 to engage a coacting shoulder of a contact, aslater described. Each of the segments 65 of the clip has a forwardextending operating member or trigger 67, preferably having a camsurfaced tip inclined outwardly, as will hereinafter appear.

As best seen in FIGURE 1, the several parts of the dielectric insert ofthe plug are apertured in alignment with each of the contact retentionclips 61 to provide elongated contact cavities 71 extending from thewire-sealing risers 72 longitudinally through the parts` 53, '51', 54and 55 of the insert, except that in the case of the plug, the forwardend of each contact cavity 71 has a restricted limiting orifice 73dimensioned to receive the pin 44 of the male contact, but to encircleit so closely as to preclude insertion of an oversize pin. The orice 73is provided,fhowever, with a tapered mouth 74, the angular walls ofwhich act as a guide orY funnel to facilitate` insertion of the pincontacts into the receptacle. The walls of the mouth portions of eachcontact cavity also intersect the smooth, tlat front face 56 of the bodymember 55 in a manner to provide peripheral ridges 76 surrounding eachof the contact cavities. It will thus be seen that when the connector iscoupled, the pressure exerted by the screw-threaded coupling ring 17will press the body member 55 tightly against the resilient sealingelement 29, establishing an overall seal across the front face of theplug body 4with individual peripheral sealing ridges around each of theindividual contact cavities. A peripheral seal around the entire contactassembly is also provided by a small forwardly projecting peripheralflange 77 at the outerl edge of the face 56 of the body member 55.

Immediately behind the limiting orice 73 of each contact cavity, thebody 55 is provided with a counterbore 78 to house the sleeve-typecontacts of the plug.

These sleeve contacts of the plug Iare similar to the pin contacts ofthe receptacle in that they have a rearward sleeve 81 to receive theinsulating layer 82 of the individual flexible conductors 83 whichextend into and are secured within the sleeve 84 at a point behind thecollar 85. The shank 86 and taper S8 of the sleeve Contact are alsosimilar to the corresponding parts of the pin contact, to provide arearwardly facing shoulder 89 similar to the rearwardly facing shoulder42 and arranged to be engaged -by the several latching teeth 66 on thecontact retention clip 61. Thus, the forward cylindrical portion 90 ofthersleeve contact may be any one of several types, so long as theforward end thereof is apertured to receive the pin 44.

The counterbores 78 of the plug body are of considerably larger diameterthan the forward sleeve portions 90 of the individual contacts -us'edtherein, so that each cavity has a longitudinal slideway or channel 91,adapted to loosely receive a tubular release member 92 having a taperedrearward end 93 underlying each of the several trigger portions 67 onthe Contact retention clip 61.

The forward end of each release tube 92 normally assumes a position asshown in FIGURE l, where it lies immediately behind, but outside of thedimensional limits of the restricted orifice 73 of the contact cavity.The tapered mouth 74 of each contact cavity is, however, provided withone or more latch release keyways, preferably in the form of radialslots 94 (FIGURE 2.) comprising extensions of the latch release channel91. In the pre-v ferred-form of the invention illustrated these keywaysare of vwidth sufciently less than the diameter of the pins 44 andcorresponding apertures 73 as to preclude acceptance of an oversize pin,and are sized to extend radially at least beyond the inner diameter oftherelease tubel in the contact cavity, the fins 97 function to forcethe.

sleeve 92 rearwardly until its cam surfaces 93 expand the retentionclips and simultaneously release the several latch teeth 66 thereof fromthe Contact shoulder 89. This leaves the entire contact assembly free tomove rearwardly, either by pulling on the individual conductors 83 orpreferably by operating the collar 98 to force thepin `9( into thesleeve of the contact and push the contact rearwardly, as lbest shown inFIGURE 8.

It is believed obvious that with the form of connector illustrated, thecontacts of both the plug and the receptacle may 'be put in placeindividually from the rear of each connector insert and may likewise beindividually removed, lby access to the front of the insert only. In thecase of both the plug and the receptacle, mounting of the contacts iseasily accomplished simply by inserting the leading end of each contactinto a cavity in the rear gronimet'of the plug or receptacle and slidingthe .contact forward with an appropriate tool (not shown) until theplural latch teeth of the collet-type contact rretention clip snap intoposition behind the locking shoulder of the contact. In the case of theplug contacts, this action earries the release tube 92'to itsforwardmost position due to a light friction drag existing between thesleeve portion 90 of the Contact and the release tube. This friction maybe created in any convenient Way, as by a spring linger 99 pierced fromthe wall of the tube and biasedinwardly to bear against the cylindricalsurface of the contact sleeve (FIGURE 3).

Removal of any individual contact is equally simple. In the case of thereceptacle, it is only necessary to slip a sleeve-like tool (not shown)on the contact pin 44 and slide it back over the-head portion 43 of thecontact, so that the leading edge of the tubular tool engages theseveral triggers 67 of the contact retention clip and flexes themoutwardly in a manner to release the latch teeth '66 thereof and allowthe contact to be drawn rearwardly from the connector insert.

In the case of the connector plug, the restricted pinlimiting apertures73 and tapered mouth portions 74 of Ithe hard front plug body 55 are soformed as to permit easy insertion of property sized pin contacts 44and, in fact, to guide the forward tips of such contacts into prefectlymating alignment with the sleeves 90 Ias the plug is coupled to thereceptacle. The apertures 73 are sized to prevent insertion of anoversize pin in the contact sleeves 90, however, as seen in FIGURE 2,from which it is apparent that the dimensional limits of the apertures(the inner diameter of the arcuate portions forming the orifice 73)corresponds to the maximum diameter of the contact pin, although theradial keyway slots 94 extend beyond these dimensional limits to permitactuation of the sleeve 92 by insertion of a properly keyed latchrelease tool. Thus, the latch release tool 95 and the latch release tube92 coact to form latch releasing instrumentalities extending from theforward face 56 of the dielectric insert to the latching meanscomprising the teeth 66 of the contact retention clips 61.

The mechanical advantages of the connector outlined above areaccomplished in the present invention, however, without sacrifice ofelectrical excellence, and by an arrangement that provides unusuallygreat reliability in operation. It should first be observed that whilethe dielectric inserts of both the plug and receptacle consist ofseveral individual parts, these coact in a manner whereby theinterfacing surfaces may be permanently bonded to each other so that theresilient gommet and resilient sealing members positioned on theopposite sides of each of the anti-deflection discs 27 and 51 coacttoencapsulate the retention clips and latching mechanisms surroundingeach individual contact so that all contacts are effectively isolatedfrom each other without air voids permitting the formation of electricalleakage paths.

Upon coupling of the plug and receptacle the contact pins 'are normallyguided in a manner to enter the sleeves of the contacts in accuratealignment, but the arrangement is such that, should one or more of thepin co-ntacts be so deformed as to fail to enter its proper aperture, itcannot possibly establish an intermittent connection. It follows thatany defects will invariably be detected during preilight check-out ofthe circuitry, assuring what has come to be known as go-no-goreliability.

It will also be seen (FIGURE l) that the face portion and tapered mouthapertures of the connector plug are formed so that, as the plug istightened into the receptacle, concentration of pressure occurring atthe peripheral ridges 76 surrounding each of the contact aperturesaccomplishes an effective vapor seal whereby each contact cavity and itskeyways are electrically isolated from all other contacts. Similarly,the marginal fiange 77 of the hard front dielectric is embedded into thesealing member 29 to isolate the entire group of contacts from theconnector shell.

I claim:

l. In an electrical connector, a dielectric body having a front faceconsisting of hard, rigid insulating material; said body having at leastone contact cavity extending longitudinally therethrough, and latchingmeans within said cavity; with each said cavity having a tapered mouthat the forward end thereof leading to a restricted orifice of fixeddimensions: said cavity also having an enlarged counterbore extendingrearwardly from said orifice with at least one narrow radial keyway slotextending outwardly from said restricted orifice and entering saidcounterbore; said counterbore in said body containing a sleeve contacttherein, with said sleeve contact having a shoulder adapted to beengaged by the aforesaid latching mean-S, and being of substantiallysmaller diameter than the counterbore to provide a slideway channeltherebetween; at least one latch releasing member permanently housed inthe aforesaid channel and longitudinally shiftable therein, whileengageable with the latching means and extending therefrom to a locationadjacent to and accessible from the keyway on the front face of thebody.

2. In an electrical connector, a dielectric 'body having a front faceconsisting of hard, rigid insulating material; said body having at leastone contact cavity extending longitudinally therethrough, and latchingmeans within said cavity; with each said cavity having a tapered mouthat the forward end thereof leading to a restricted orifice of fixeddimensions: said cavity also having an enlarged counterbore extendingrearwardly from said orifice with at least one narrow radial keyway slotextending outwardly from said restricted orifice to the edge of thetapered mouth, and entering said counterbore; said counterbore in saidbody containing a sleeve contact therein, with said sleeve contacthaving a shoulder adapted to be engaged by the aforesaid latching means,and being of substantially smalle-r diameter than the counterbore toprovide a slideway channel therebetween; at least one latch releasingmember permanently housed in the aforesaid channel and longitudinallyshiftable therein, while engageable with the latching means andextending therefrom to a location adjacent to and accessible from thekeyway on the front face of the body: said latch releasing membercomprising a sleeve received within the aforesaid counterbore of thecontact cavity and slidable on but frictionally secured to the forwardportion of said sleeve contact.

3. In an electrical connector comprising a plug and receptacle, eachhaving a tubular metal shell adapted to couple in telescoping relationwith the other; said plug and receptacle each having a dielectric insertincluding a relatively thin, rigid disc with at least one retention clipfor mounting telescoping pin and sleeve contacts uniting the plug andthe receptacle; with a yieldale resilient grommet on the rearward faceof each of said discs and a yieldable resilient sealing member on theforward face of each of said discs coacting to encapsulate the retentionclips thereon; the combination of a front face piece of the dielectricbody consisting of hard, rigid insulating material; said piece having arearward surface bearing against the sealing member of the plug andhaving lat least one contact cavity extending longitudinallytherethrough and leading to a closed-entry orifice closely fitting thediameter of the aforesaid pin but having a larger counterbore extendingrearwardly from said orifice; with at least one keyway in the front facepiece; each of said counterbores in said body containing an aforesaidsleeve contact therein, with said sleeve contacts of substantiallysmaller diameter than the counterbores to provide a slidewaytherebetween; said sleeve contacts having a shoulder adapted to beengaged by at least one latching device carried by `an aforesaid Contactretention clip; together with at least one latch releasing memberpermanently housed in the aforesaid slideway and longitudinallyshiftable therein, while en- -gageable with a trigger portion of thelatching device and extending therefrom to a location accessible fromthe front face of the body, to release said latching device and permitremoval of the contact; said latch releasing member having a forward endnormally projecting beyond the forward end of the contact to a locationadjacent the mouth of the contact cavity and underlying at least aportion of the aforesaid keyway therein.

4. In an electrical connector comprising a plug and receptacle, eachhaving a tubular metal shell adapted to couple in telescoping relationwith the other; said plug and receptacle each having a dielectric insertincluding a relatively thin, rigid disc with at least one retention clipfor mounting telescoping pin and sleeve contacts uniting the plug andthe receptacle; with .a yieldable resilient grommet on the rearward faceof each of said discs and a yieldable resilient sealing member on theforward face of each of said discs coacting to encapsulate the retentionclips thereon; the combination of a front face piece of the dielectricybody consisting of hard, rigid insulating material; said piece having arearward surface bearing against the sealing member of the plug andhaving at least one contact cavity extending longitudinallytherethrough, with said cavity having a tapered mouth at the forward endthereof leading to a closed-entry orifice having a minor dimensionclosely fitting the diameter of the aforesaid pin contact and a majordimension substantially greater; but having a larger counterboreextending rearwardly from said orice; with at least one narrow radialkeyway slot in the tapered mouth, and a smooth, at forward face with aperipheral edge surrounding the mouth of each entrance orice and adaptedto bear against the resilient sealing member of the receptacle oftheconnector to isolate each contact cavity; and a marginal flange on saidbody engageable with said sealing member to isolate the entire facethereoffrom the shell; each of said counterbores in said body containingan aforesaid sleeve contact therein, with said sleeve contacts ofsubstantially smaller diameter than the counterbores to provide aslideway therebetween; said sleeve contacts having a shoulder adapted tobe engaged by at least one latching device carried by an aforesaidcontact retentionclip together with at least one latch releasing memberpermanently housed in the aforesaid slideway and longitudinallyshiftable therein, while engageable with a trigger portion of thelatching device and extending therefrom to `a location accessible fromthe front face of the body, to release said latching -device andvpermitwithdrawal of the contact rearwardly thro-ugh the aforementionedresilient grommet; saidy latch releasing member comprising a sleevewithin the aforesaid counterbore of the Contact cavity and slideable onbut frictionally secured to the forward portion of said sleeve contact;said sleeve having a forward end normally projecting beyond the mouth ofthe contact cavity and underlying at least a portion of the aforesaidradial keyway slot therein.

5. In an electrical connector comprising a plug and receptacle, eachhaving a tubular metalshell adapted to couple in telescoping relationwith the other.; said plug and receptacle each having a dielectricinsert surroundingV at least one electrical contact of telescoping type4and including a relatively thin, rigid disc carrying at least oneretention `clip for mounting said telescoping contacts uniting the plugand the receptacle, with a yieldable resilient grommet on the rearwardface of each of said discs and a yieldable resilient sealing member onthe forward face of each of said discs coacting to encapsulate thecontacts and retention clips thereonythe combination of a front piecefor one of said dielectric inserts consisting of hard, rigid insulatingmaterial; said front piece having at least one contact apertureextending longitudinally therethrough and having a rearward face bearingagainst one of thel aforesaid sealing members and a front face adaptedto bear against the other of said resilient sealing members of theconnector; with each said contact aperture having an enlarged taperedmouth at the front face with a peripheral edge indenting the resilientsealing member to isolate each contact cavityv from the others and amarginal ange on said front piece engageable with said sealing member`to isolate the entire face thereof from the shell.

6, In an electrical connector comprising a plug andreceptacle, eachhaving a tubular metal shell adapted to couple in telescoping relationwith the other; said plug and receptacle each having a dielectric insertsurrounding at least one electrical Contact lof telescoping type andincluding la relatively thin, rigid disc carrying at least oneretentionclip for mounting said telescoping contacts uniting the plug and thereceptacle, witha yieldable resilient grommet on the rearward face ofeach of said discs and a yieldable resilient sealing member ontheforward face of each of said discs coacting to encapsulate the contactsand retention clips thereon; the combination of a front piece for one ofsaid dielectric inserts consisting of hard, rigid insulating material;said front piece having at least one contact aperture extendinglongitudinally therethrough and having a rearward face bearing againstone of the aforesaidsealing members and a front face adapted to bearagainst the other of said resilient sealing members of the connector;with each said contact aperture having a peripheral edge indenting theresilient sealing member to isolate each Contact cavity from the others.

References Cited UNITED STATES PATENTS' 2,352,618 7/1944 Daenz 339-1932,691,147 10/1954 lSutton et al. 339-217 2,762,206 9/1956 Knohl 339-2172,944,241 7/1960 Londell 339-258 X 3,170,752 2/1965 Van Horssen l339-217 3,221,292 11/1965 Swanson et al. 339-217 MARVIN A. CHAMPION,Primary Examiner.

PATRICK A. CLIFFORD, Examiner.

1. IN AN ELECTRICAL CONNECTOR, A DIELECTRIC BODY HAVING A FRONT FACECONSISTING OF HARD, RIGID INSULATING MATERIAL; SAID BODY HAVING AT LEASTONE CONTACT CAVITY EXTENDING LONGITUDINALLY THERETHROUGH, AND LATCHINGMEANS WITHIN SAID CAVITY; WITH EACH SAID CAVITY HAVING A TAPERED MOUTHAT THE FORWARD END THEREOF LEADING TO A RESTRICTED ORIFICE OF FIXEDDIMENSIONS: SAID CAVITY ALSO HAVING AN ENLARGED COUNTERBORE EXTENDINGREARWARDLY FROM SAID ORIFICE WITH AT LEAST ONE NARROW RADIAL KEYWAY SLOTEXTENDING OUTWARDLY FROM SAID RESTRICTED ORIFICE AND ENTERING SAIDCOUNTERBORE; SAID COUNTERBORE IN SAID BODY CONTAINING A SLEEVE CONTACTTHEREIN, WITH SAID SLEEVE CONTACT HAVING A SHOULDER ADAPTED TO BEENGAGED BY THE AFORESAID LATCHING MEANS, AND BEING OF SUBSTANTIALLYSMALLER DIAMETER THAN THE COUNTERBORE TO PROVIDE A SLIDEWAY CHANNELTHEREBETWEEN; AT LEAST ONE LATCH RELEASING MEMBER PERMANENTLY HOUSED INTHE AFORESAID CHANNEL AND LONGITUDINALLY SHIFTABLE THEREIN, WHILEENGAGEABLE WITH THE LATCHING MEANS AND EXTENDING THEREFROM TO A LOCATIONADJACENT TO AND ACCESSIBLE FROM THE KEYWAY ON THE FRONT FACE OF THEBODY.